Conventionally, an apparatus has been proposed which is mounted on a vehicle and recognizes a lane along which the vehicle travels by detecting a white line (lane-dividing line) drawn on a road surface in order to divide lanes, from an image obtained by photographing with a camera. A technology related to this type of apparatus has been known which extracts an edge point corresponding to the white line from a photographed image and determines whether the white line is a solid line or a broken line depending on whether or not a time-series variance value in the number of measurements of the edge point is not more than a threshold value (Patent Literature 1).